Patent Document 1 discloses a filter device that includes an inflow pipe provided in a tangential direction with respect to the circumferential wall surface of a cylindrical main body container with a vertically disposed central axis and configured to introduce liquid containing an object to be separated, a cylindrical filter element disposed coaxially with the main body container in the main body container and configured to remove foreign matter contained in the liquid, an outflow pipe through which the liquid filtered by the filtration element flows out, and a bubble discharging pipe provided on the upper portion side of the main body container in a tangential direction with respect to the circumferential wall surface of the main body container and configured to discharge bubbles contained in the liquid together with the liquid.